[R] Unequal sample sizes when calculating power

Peter Dalgaard p.dalgaard at biostat.ku.dk
Wed Jan 25 17:24:27 CET 2006

Farrel Buchinsky <fbuchins at wpahs.org> writes:

> Power calculations two sample test for proportions is very useful. Is there
> a way however, to get away from the two samples being of the same size. What
> would happen if one had n=15 in the one sample and n=45 in the other sample.

Take a look at


That's for t-tests, but similar modifications might be used for

   O__  ---- Peter Dalgaard             Øster Farimagsgade 5, Entr.B
  c/ /'_ --- Dept. of Biostatistics     PO Box 2099, 1014 Cph. K
 (*) \(*) -- University of Copenhagen   Denmark          Ph:  (+45) 35327918
~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)                  FAX: (+45) 35327907

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